For its entire his­to­ry, macro­eco­nom­ics has been dom­i­nat­ed by math­e­mat­i­cal mod­els that ignore the exis­tence of mon­ey, debt and bank­ing, and that per­ceive the econ­o­my’s move­ment through time as tran­si­tions from one state of equi­lib­ri­um to anoth­er.

At any point in his­to­ry, these would be hero­ic assump­tions. Could it real­ly be true that mod­els with­out either mon­ey or insta­bil­i­ty are prov­ably supe­ri­or at pre­dict­ing the econ­o­my’s future course than mod­els in which mon­ey and bank­ing exist, and in which the mod­el econ­o­my can be out of equi­lib­ri­um? If not, is it the case then that such mod­els are sim­ply too dif­fi­cult to construct—that the best we can do is pre­tend that the econ­o­my does­n’t have banks or mon­ey, and that it’s always in equi­lib­ri­um, even if we know these assump­tions are false?

Before the cri­sis of 2007, few non-econ­o­mists even asked those ques­tions, because there seemed to be no need to chal­lenge what econ­o­mists did. The econ­o­my, after all, was going gang­busters. Pro­fes­sion­al econ­o­mists, using the very lat­est math­e­mat­i­cal mod­els of the econ­o­my, took cred­it for its ster­ling per­for­mance, and pre­dict­ed more of the same for the fore­see­able future.

Robert Lucas, the father of “Ratio­nal Expec­ta­tions Macro­eco­nom­ics”, assert­ed that the “macro­eco­nom­ics … has suc­ceed­ed. Its cen­tral prob­lem of depres­sion pre­ven­tion has been solved, for all prac­ti­cal pur­pos­es, and has in fact been solved for many decades.”[1] Ben Bernanke laud­ed “improved con­trol of infla­tion” as the cause of “the Great Mod­er­a­tion”, which he described as “this wel­come change in the econ­o­my.” [2] In June 2007, the OECD, guid­ed by its macro­eco­nom­ic mod­el, opined that “the cur­rent eco­nom­ic sit­u­a­tion is in many ways bet­ter than what we have expe­ri­enced in years… Our cen­tral fore­cast remains indeed quite benign”. [3]

Then all hell broke loose, and almost five years lat­er, it shows no signs of abat­ing. Now non-econ­o­mists are chal­leng­ing what econ­o­mists do, and final­ly real­iz­ing what a minor­i­ty of dis­si­dents with­in eco­nom­ics have long known: these assump­tions are not mere­ly hero­ic, they are both false and unnec­es­sary. Mon­ey, debt and dis­e­qui­lib­ri­um dynam­ics play cru­cial roles in the actu­al behav­iour of the econ­o­my, and it is rel­a­tive­ly easy to devel­op math­e­mat­i­cal mod­els which include mon­ey and banks, and in which the econ­o­my is always in dis­e­qui­lib­ri­um. I should know: it’s what I do, and it’s why I was one of two math­e­mat­i­cal econ­o­mists who saw this cri­sis com­ing, and warned of it pub­licly before it hap­pened (the oth­er was the late Wynne God­ley). [4]

For eco­nom­ics to have a future, it has to aban­don the obses­sion with equi­lib­ri­um mod­el­ling, and real­is­ti­cal­ly incor­po­rate mon­ey, bank­ing and finance into macro­eco­nom­ics. Both things are, as I’ve said, not hard to do.

The start­ing point for mod­el­ling any process in a true sci­ence is a posi­tion of disequilibrium—Newton, after all, mod­elled grav­i­ty by con­sid­er­ing a falling apple, not one at rest! Econ­o­mists have to aban­don their fetish with “com­par­a­tive sta­t­ics” and instead mod­el process­es of change. Dynam­ics has to be the core of eco­nom­ic analy­sis, not equi­lib­ri­um.

Mon­ey is also eas­i­ly mod­elled by bor­row­ing the basic tool of the accoun­tant, dou­ble-entry book­keep­ing. [5] Mon­ey and debt are cre­at­ed by book­keep­ing entries, and the same par­a­digm can be used to derive dynam­ic mod­els of the flow of mon­ey in one direc­tion, pro­pelling the move­ment of goods and finan­cial assets in the oth­er.

The dif­fi­cul­ty in devel­op­ing a mon­e­tary dynam­ic macro­eco­nom­ics comes not from the tools them­selves, but from the beliefs that have to be aban­doned to employ them sensibly—from oth­er assump­tions that Neo­clas­si­cal econ­o­mists have made to “sim­pli­fy” analy­sis that instead have made it almost impos­si­ble to under­stand the real world. There are enough of these to lit­er­al­ly fill a book—to whit, my Debunk­ing Eco­nom­ics [6]—but I’ll sin­gle out just three:

“Ratio­nal” expectations—which real­ly means assum­ing that every­one can accu­rate­ly pre­dict the future (and there­fore avoid any calami­ties like the one we are in right now);

Rep­re­sen­ta­tive agents—which real­ly means assum­ing that there’s only one per­son in the econ­o­my, who pro­duces and con­sumes just one com­mod­i­ty; and

Per­ceiv­ing macro­eco­nom­ics as applied micro­eco­nom­ics

This last false belief, and not a quest for greater real­ism, was the dri­ving force behind the devel­op­ment of macro­eco­nom­ics since WWII. It was a fool’s errand, since as physi­cists real­ized decades ago, “More Is Different”—to quote the title of a famous paper from Physics Nobel Lau­re­ate Philip Ander­son. [7] Biol­o­gy can­not be treat­ed as mere­ly applied chem­istry, even though the ele­men­tary build­ing blocks of liv­ing enti­ties are chem­i­cals, because prop­er­ties emerge from the inter­ac­tions of these chem­i­cals that can’t be explained from the chem­i­cals alone.

We call one of these emer­gent prop­er­ties “Life”. We know a great deal about chem­istry, but no chemist has as yet cre­at­ed life. The attempt to reduce macro­eco­nom­ics to applied micro­eco­nom­ics was as futile a quest.

About Steve Keen

I am Professor of Economics and Head of Economics, History and Politics at Kingston University London, and a long time critic of conventional economic thought. As well as attacking mainstream thought in Debunking Economics, I am also developing an alternative dynamic approach to economic modelling. The key issue I am tackling here is the prospect for a debt-deflation on the back of the enormous private debts accumulated globally, and our very low rate of inflation.

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